JP3343775B2 - Ultrasonic cleaning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic cleaning apparatus for cleaning an object to be cleaned such as a semiconductor wafer or a glass substrate for an LCD using ultrasonic waves.

[0002]

2. Description of the Related Art Generally, in a manufacturing process of a semiconductor manufacturing apparatus, a semiconductor wafer, a glass substrate for an LCD, and the like are washed by sequentially immersing them in a processing tank in which a processing solution such as a chemical solution or a rinsing solution (cleaning solution) is stored. Liquid treatment methods are widely adopted.

FIG. 1 shows an example of such a liquid processing method.
As shown in FIG. 6, a plurality of diaphragms 3 are bonded to an object to be cleaned, for example, a semiconductor wafer W (hereinafter, referred to as a wafer) and a cleaning tank 2 for storing a cleaning liquid, for example, pure water 1 by, for example, an adhesive. A sonic cleaning device is known. According to this ultrasonic cleaning apparatus, an output voltage, for example, a high frequency voltage of 800 KHz to 1 MHz is applied from the oscillator 4 to each of the vibration plates 3 to excite the vibration plates 3 to remove particles and the like adhering to the wafer W. be able to. Here, the relationship between the particle removal rate (A) and the sound pressure (B) is as follows: A∝T × B ² (where T is a proportional constant).

As can be seen from the above equation, the excitation of the vibration plate 3, that is, the sound pressure and the particle removal rate are in a proportional relationship. Therefore, the vibration plate 3 is excited and the sound pressure is increased to adhere to the wafer W. Particles and the like can be removed.

[0005]

However, in this type of conventional cleaning apparatus, since the diaphragm 3 is driven by a plurality of independent oscillators 4, the diaphragm 3 does not have to be separated for insulation. Not be. Therefore, a gap is generated between the diaphragms, and interference of ultrasonic waves is generated in the gap, so that a portion having a non-uniform sound pressure is generated as shown in FIG.
Therefore, there is a problem that the removal rate of the particles becomes non-uniform and uneven cleaning occurs (see FIG. 17B).

As a means for solving this problem, there has been proposed an ultrasonic cleaning apparatus in which a step is provided on a mounting surface of a diaphragm, and the diaphragm is mounted on both sides with the step being separated (Japanese Unexamined Patent Publication No. Hei. 243203).
However, even in the technique described in Japanese Patent Application Laid-Open No. 5-243203, a gap is formed between adjacent vibrations due to a step, so that interference of ultrasonic waves occurs and the sound pressure cannot be made uniform. There is a problem that the removal cannot be made uniform, resulting in uneven cleaning. Also,
Since the diaphragm is attached by providing a step on the attachment surface of the diaphragm, there is a problem that accuracy is required for assembly and the device becomes complicated and large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims at eliminating the interference of ultrasonic waves between adjacent diaphragms and improving the cleaning efficiency by making the particle removal rate uniform with a uniform sound pressure distribution. It is an object of the present invention to provide an improved ultrasonic cleaning device.

[0008]

In order to achieve the above object, a first ultrasonic cleaning apparatus of the present invention comprises a cleaning tank for storing an object to be cleaned and a cleaning liquid, and a plurality of vibration tanks attached to the cleaning tank. An ultrasonic cleaning device comprising a plate and
The output phases of a plurality of power supply units for driving the respective diaphragms are controlled so as to have the same phase by the same oscillation source (claim 1).

A second ultrasonic cleaning apparatus according to the present invention comprises: a cleaning tank for storing an object to be cleaned and a cleaning liquid; a vibration transmission tank for storing a vibration transmitting liquid in contact with a bottom portion of the cleaning tank; In an ultrasonic cleaning apparatus including a plurality of diaphragms attached to the vibration propagation tank, the phases of outputs of a plurality of power supply units for driving the respective diaphragms are controlled to have the same phase by the same oscillation source. (Claim 2).

In the present invention, a gap may be formed between adjacent diaphragms as long as the respective diaphragms are adjusted in phase by the same control means. It is better to make the gap as small as possible (claim 3).

It is preferable to control the variation of the natural frequency of each diaphragm by frequency modulation.

According to the first ultrasonic cleaning apparatus of the present invention, the phases of the outputs of the plurality of power supply units for driving the respective diaphragms are matched by the same oscillation source, so that the phase of the phase between the adjacent diaphragms can be adjusted. Since the interference due to the displacement can be eliminated, a uniform sound pressure distribution can be obtained, and the particle removal rate can be made uniform.

According to the second ultrasonic cleaning apparatus of the present invention, the cleaning tank for storing the object to be cleaned and the cleaning liquid, and the vibration transmitting tank for storing the vibration transmitting liquid in contact with the bottom of the cleaning tank. And an ultrasonic cleaning apparatus including a plurality of diaphragms attached to the vibration propagation tank, so that the phases of outputs of a plurality of power supply units for driving the respective diaphragms have the same phase by the same oscillation source. Since the control is performed, the removal rate of the particles can be made uniform, and the cleaning tank can be prevented from being damaged by excessive ultrasonic vibration (claim 2).

Further, by making the gap between the adjacent diaphragms as narrow as possible, the sound pressure distribution and the particle removal rate can be more reliably made uniform.

Further, by the frequency modulation of the oscillation source, the ultrasonic output of the diaphragm can be averaged within the range of the variation of the natural frequency of each diaphragm. The particle removal rate can be made uniform (claim 4).

Further, since the diaphragm can be attached without providing a step in the cleaning tank, the assembly of the apparatus can be facilitated. Further, since a plurality of diaphragms are controlled by the same oscillation source, The number of constituent members can be reduced, and the size of the apparatus can be reduced.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. In this embodiment, a case where the present invention is applied to a semiconductor wafer cleaning processing apparatus will be described.

FIG. 1 is a schematic sectional view showing a first embodiment of the ultrasonic cleaning apparatus according to the present invention.

The ultrasonic cleaning apparatus is connected to a cleaning tank 10 containing a semiconductor wafer W (hereinafter, referred to as a wafer) to be cleaned and a cleaning liquid, for example, pure water 1, and is connected to an upper end opening of the cleaning tank 10. An outer tank 20 for receiving the pure water 1 overflowing from the cleaning tank 10, and holding means for holding the wafer W in the cleaning tank 10, for example, a wafer boat 30. The outer tub 20 is provided with a drain port 21, and a drain pipe 23 is connected to the drain port 21 via a drain valve 22. A supply unit (not shown) for supplying the pure water 1 into the cleaning tank 10 is provided at the bottom of the cleaning tank 10.

At the bottom of the washing tank 10, a plurality of, for example, two diaphragms 40a, 40b are in close proximity, for example, 0.1.
It is bonded with an adhesive or the like at an interval of about 0.2 mm. In this case, the vibration plates 40a and 40b are formed of a ceramic plate material, and one of the vibration plates 40a is a first oscillator 6 having an oscillation source 50 and a power supply unit PU1.
0a, the other diaphragm 40b is connected to a second oscillator 60b having a power supply unit PU2, and the second oscillator 60b has its drive output phase controlled by the oscillation source 50 of the first oscillator 60a. It has become so.
That is, a power supply unit for exciting the diaphragms 40a and 40b
The configuration is such that a uniform sound pressure distribution can be obtained by matching the phases of the outputs of PU1 and PU2 .

In this case, the phase of the second oscillator 60b is controlled by the oscillation source 50 provided in the first oscillator 60a, but it is not necessary to adopt such a structure.
As shown in FIG. 3, both the first oscillator 60a and the second oscillator 60b may include only the power supply units PU1 and PU2, and the phases of these oscillators 60a and 60b may be controlled by the same oscillation source 50A. .

As described above, in order to drive both diaphragms 40a and 40b in the same phase, both diaphragms 40a and 40b are arranged without a gap, specifically, the gap is set to 0.1 to 0.2 mm. Can be. Therefore, the non-uniformity due to the interference of the ultrasonic wave is eliminated, and the sound pressure distribution can be made uniform as shown in FIG. 2A, and the particle removal rate can be made uniform as shown in FIG. 2B. can do.

In the above embodiment, the case where the number of diaphragms is two has been described. However, even when the number of diaphragms is three or more, the phase of each diaphragm can be similarly controlled by the same oscillation source. For example, as shown in FIGS. 4 and 5, the diaphragms 40 are arranged at appropriate intervals in two rows at the bottom of the cleaning tank 10 and, for example, two diaphragms 40 on the left and right are used as one unit for vibration. The plate groups 41a, 41b, 41c... 41n are formed, and these diaphragm groups are respectively connected to the power supply units PU1, PU2, P
U3... First to n-th oscillators 60a to 60n
60n, and each of the oscillators 60a to 60n is controlled by the same oscillation source 50.

With the above arrangement, the phases of the respective diaphragms (specifically, the respective diaphragm groups 41a to 41n) can be matched, and a uniform sound pressure distribution can be obtained. Therefore, particles and the like adhering to a plurality of, for example, 50 wafers W accommodated in the cleaning tank 10 at appropriate intervals can be efficiently removed. Further, the diaphragms 40a, 40a,
0b can be attached, so that assembly of the device can be facilitated. Further, since the plurality of diaphragms 40a, 40b are controlled by the same oscillation source 50, the number of constituent members can be reduced and the size of the device can be reduced. Can be achieved.

FIG. 6 shows still another embodiment (fourth embodiment). The ultrasonic cleaning apparatus shown in FIG. 6 is connected to a cleaning tank 87 made of, for example, quartz, which contains a wafer W to be cleaned and a cleaning liquid 88, and is connected to an upper end opening of the cleaning tank 87 and overflows from the cleaning tank 87. An outer tank 20 for receiving the cleaning liquid 88, a holding means for holding the wafer W in the cleaning tank 87, for example, the wafer boat 30, and a vibration propagation tank 85 for storing a liquid for vibration propagation, for example, water 86. . The washing tank 87 is supported by a support member (not shown) so that the bottom surface of the washing tank 87 is placed in a state of bathing in water (contacting the liquid for vibration propagation) in the tank 85 for vibration propagation. By arranging the cleaning tank 87 as described above, the cleaning tank 87 is caused by excessive ultrasonic vibration.
Can be prevented from being damaged. The vibration propagation tank 85 includes a tank body 85a formed of a rectangular frame made of, for example, PP (polypropylene) resin, and a tank body 8a.
The vibration transmission plate 84 is made of, for example, stainless steel and is fixed to an inward flange 85b provided at the lower end of the base 5a. In this case, the vibration transmission plate 84 is adhered to the tank main body 85a with, for example, an adhesive or the like, or is fixed by bolting via packing (not shown).

The vibration propagation tank 85 configured as described above.
The vibration plate 82 is adhered to the lower surface of the vibration transmission plate 84 with an adhesive or the like at an appropriate interval as in the above-described embodiment. In this case, the diaphragms 82 are arranged in two rows as shown in FIG.
3a, 83b, and 83c, and each diaphragm group 83a, 8
3b and 83c are oscillators (power supply units) 81, respectively.
a, 81b, 81c. Among them, the diaphragm group 83a is connected to the main oscillator 81a, and the diaphragm group 8a
3b and 83c are connected to the sub oscillators 81b and 81c, respectively.

As shown in FIG. 8, the main oscillator 81a includes a transmission circuit 51 for frequency modulation (FM modulation), a first-stage amplification circuit 52 for amplifying a vibration signal from the transmission circuit 51, and a further amplification of the vibration signal. And a matching circuit 54 that matches the vibration signal amplified by the power amplification circuit 53 to output the vibration signal to the diaphragm group 83a. The main oscillator 81a includes a power amplifier circuit 5
3, an output adjustment circuit 58 for adjusting the output, a control circuit 57 for sending a control signal to the output adjustment circuit 58, and an output adjustment rotary thumb switch 56, and a power supply circuit 55 connected to the power supply A; Is provided with an output meter 59 for monitoring.

On the other hand, the sub oscillators 81b and 81c have the same circuit configuration as the output side of the main oscillator 81a.
The power amplifier 53 and the matching circuit 5 that are branched and connected from the output side of the first-stage amplifier 52 of the main oscillator 81a.
4. It includes an output adjustment circuit 58 of the power amplification circuit 53, a control circuit 57A of the output adjustment circuit 58, a power supply circuit 55 connected to the power supply A, and an output meter for monitoring an output vibration signal. Further, the control circuit 57 of the main oscillator 81a and the control circuit 57A of the sub oscillators 81b and 81c.
Are connected via a connector 61 to the main oscillator 8.
Host computer HC connected to the control circuit 57 of FIG.
Oscillators 81a, 81b, 8 based on a control signal from
1c is configured to be controlled. In FIG. 8, reference numeral 62 denotes a short connector, 63
Is termination.

The vibration propagation tank 85 configured as described above.
A group of diaphragms 83a, 83b,
By bonding the same transmission circuit 51 to the diaphragm groups 83a to 83c, the ultrasonic output of the diaphragm 82 can be averaged within the range of variation in the natural frequency of each diaphragm 82. Can be. That is, when a constant frequency is applied to each diaphragm 82 without using the transmitting circuit 51 for frequency modulation, as shown in FIGS. 9A and 9B to 9D, each diaphragm group Although the output sound pressure varies due to the difference in the natural frequencies of 83a to 83c,
By performing frequency modulation (FM modulation) on the natural frequency using No. 1, the output sound pressure viewed as a time average can be controlled to be constant (see FIGS. 10A and 10B).

The vibration from the diaphragm 82 of each of the diaphragm groups 83a to 83c whose output sound pressure is controlled to be constant as described above is transmitted to the vibration transmitting plate 84 and also transmitted to the water 86, Is propagated to the bottom surface of the cleaning tank 87 and then to the cleaning liquid 88 contained in the cleaning tank 87, and the wafer W in the cleaning tank 87 is cleaned.
Therefore, by performing the FM modulation within the range of the variation of the natural frequency of the vibration plate 82, the ultrasonic intensity as viewed on a time average can be kept constant, so that the particle removal rate can be further improved.

In the fourth embodiment, the case where the wafer is ultrasonically cleaned through the vibration propagation tank 85 has been described. However, as in the first to third embodiments, the cleaning tank 8 is cleaned.
A structure may be adopted in which the diaphragm 82 is bonded to the bottom surface of the base 7. Further, in the first to third embodiments, the cleaning may be performed through the vibration propagation tank 85 as in the fourth embodiment.

The ultrasonic cleaning apparatus configured as described above can be used as a single cleaning processing apparatus, or can be used by being incorporated in a wafer cleaning / drying processing system. For example, as shown in FIG. 11, the wafer cleaning / drying processing system includes a carry-in section 70a for storing an unprocessed wafer W, a cleaning / drying processing section 71 for performing cleaning processing and drying processing for the wafer W, An unloading section 70b for accommodating the processed wafers W, and a plurality of, for example, three wafer chucks 80 disposed beside the cleaning / drying processing section 71 for transferring a predetermined number of, for example, 50 wafers W. Unit is configured.

The cleaning / drying processing section 71 has a carry-in section 7
0a, a first chuck cleaning / drying unit 72, a first chemical processing unit 73, a first water cleaning processing unit 74, and a second chemical including the above-described liquid processing apparatus in a linear manner from the discharge unit 70b to the discharge unit 70b. For example, an ammonia solution processing unit 75, a third chemical solution such as hydrofluoric acid (aqueous HF solution)
A processing unit 76, a second water cleaning processing unit 77 using an ultrasonic cleaning apparatus according to the present invention, a second chuck cleaning / drying unit 78, and a drying processing unit 79 are provided. Note that the ultrasonic cleaning device according to the present invention can be used for the first water washing processing unit 73.

In the cleaning / drying processing system configured as described above, the unprocessed wafer W is sequentially transferred to the processing units 73, 74, 75, 76, and 77 of the cleaning / drying processing section 71 by the wafer chuck 80. Conveyed,
After a predetermined chemical solution treatment and cleaning treatment are performed, the substrate is conveyed to the drying treatment unit 79 and dried.

In the above embodiment, the case where the ultrasonic cleaning apparatus of the present invention is applied to a semiconductor wafer cleaning processing apparatus has been described. Of course, it can also be applied.

[0036]

Next, the ultrasonic sound pressure at the boundary between the diaphragms in the ultrasonic cleaning apparatus according to the first to third embodiments of the present invention and the boundary between the diaphragms in the conventional ultrasonic cleaning apparatus will be described. An experiment for comparing the reduction will be described.

In conducting the above experiment, an experimental apparatus as shown in FIG. 12 was prepared, and the sound pressure was measured under the following conditions. The experimental apparatus is configured such that a vibrator 92 (diaphragm) is attached to the bottom of a stainless steel tank 91 containing water 90, and this vibrator 92 can be driven by two oscillators 93, 93. The sound pressure sensor 94 inserted in the water 90 accommodated in the tank 91 is horizontally moved by the moving mechanism 95, and the sound pressure signal detected by the sound pressure sensor 94 is measured by the ultrasonic sound pressure meter 96. , And a recorder 97.

Measurement Method The sound pressure distribution on the vibrating surface is measured. 77 of the vibrating surface
Measure points. The sound pressure sensor 94 is scanned on the vibration surface at a constant speed, and the signal from the sound pressure sensor 94 is recorded in the recorder 97.

Measurement conditions Liquid temperature: 50 ° C. (city water) Liquid depth: 220 mm Measurement point: 150 mm from vibrating surface Ultrasonic strength: 2.7 W / cm ² Sensor pickup diameter: 7 mmφ Scan speed of sensor: 2.7 mm / sec Paper feed speed of recorder: 1.3 mm / sec Under the above measuring method and conditions, two vibrators 92, 92 having a length of 107.5 mm as shown in FIG.
m, the sound pressure sensor 94 is scanned from point A to point B, and the excitation f
= 985 KHz, FIG. 13 (b)
The result as shown in FIG. The sound pressure sensor 94
Are scanned in the same manner, and excitation f
When a case where 1 = 983 KHz and f2 = 982 KHz was measured, a result as shown in FIG. 13C was obtained.
Excitation f3 = 983 KHz at the same frequency and opposite phase
As a result, a result as shown in FIG. 13D was obtained.

As a result of the above experiment, when excited at different frequencies (the above case) and when excited at the same frequency and in the opposite phase (the above case), the sound was generated in the gap between the vibrators 92 and 92. It can be seen that the pressure decreases by about 0.6 to 0.7 V in all cases, and when excitation is performed in synchronization with the above (in the above case), 0.2 V is applied to the gap between the vibrators 92 and 92. The sound pressure was low.

Further, as shown in FIG.
When four 23 mm vibrators 92 of 23 mm were arranged in close contact with each other, the sound pressure sensor 94 was scanned from point A to point B, and the case where excitation f4 = 984 KHz was measured in synchronization with FIG. ) Were obtained. Further, the length is 123 mm as shown in FIG.
Are arranged separately with a gap of 2 mm in the widthwise direction, and the sound pressure sensor 94 is moved from the point A to the point B.
Is scanned and synchronized with excitation f5 = 98
When the measurement was performed at a frequency of 3 KHz, a result as shown in FIG. 15B was obtained. In addition, the length 1
Four 23 mm vibrators 92 are divided and arranged with a gap of 2 mm in the transverse direction, and the sound pressure sensor 94 is similarly scanned from point A to point B, and excitation f6 = When the case of 983 KHz and f7 = 984 KHz was measured, the result as shown in FIG. 15C was obtained.

As a result of the above experiment, when a gap of 2 mm was provided and the excitation was performed synchronously (the above case), the vibrator 9
It can be seen that the sound pressure drops by about 0.5 V in the gap between the oscillators 92 and 92, and when the gap 2 mm is provided and excited at different frequencies (the above case),
It was found that the sound pressure dropped by about 0.75 V in the gap between the 92. On the other hand, when the vibrators 92, 92 were closely contacted and excited in synchronization (the above case), a sound pressure drop of 0.15 V was observed between the vibrators 92, 92. . Therefore, it is preferable to reduce the gap between the vibrators 92, 92 as much as possible.

[0043]

As described above, according to the present invention, because of the above-described configuration, the following excellent effects can be obtained.

1) According to the first aspect of the present invention, the phases of the outputs of a plurality of power supply units for driving each diaphragm are controlled by the same oscillation source so as to have the same phase.
Since it is possible to eliminate interference due to phase shift between adjacent diaphragms, a uniform sound pressure distribution can be obtained,
The particle removal rate can be made uniform. Therefore, it is possible to eliminate uneven cleaning and improve the cleaning efficiency. Further, since the diaphragm can be attached without providing a step in the cleaning tank, assembly of the apparatus can be facilitated, and moreover, a plurality of diaphragms can be controlled by the same oscillation source. The number of members can be reduced, and the size of the apparatus can be reduced.

[0045] 2) According to the second aspect of the present invention, fitted with a plurality of diaphragm-chamber vibration propagation that houses the vibration propagation liquid in contact with the bottom portion of the cleaning tank, to drive the vibrating plate more
The output phase of the power supply unit is controlled to have the same phase by the same oscillation source, so that the particle removal rate can be made uniform and the cleaning tank is not damaged by excessive ultrasonic vibration. Can be prevented.

3) According to the third aspect of the present invention, the sound pressure distribution and the particle removal rate can be made more uniform by making the gap between the adjacent diaphragms as narrow as possible. Therefore, in addition to the above 1) and 2), it is possible to more reliably eliminate the uneven cleaning, and it is possible to improve the cleaning efficiency and the reliability of the cleaning apparatus.

4) According to the fourth aspect of the invention, the ultrasonic output of the diaphragm can be averaged within the range of the variation of the natural frequency between the diaphragms by performing frequency modulation in the oscillation source. Further, the sound pressure distribution and the particle removal rate can be made uniform.

Therefore, in addition to the above 1) to 3), it is possible to more reliably eliminate unevenness in cleaning, and it is possible to improve the cleaning efficiency and the reliability of the cleaning apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of an ultrasonic cleaning device according to the present invention.

FIGS. 2A and 2B are a graph (a) showing a relationship between a sound pressure and a position of a diaphragm and a graph (b) showing a relationship between a particle removal rate and a position in the first embodiment.

FIG. 3 is a schematic sectional view showing a second embodiment of the ultrasonic cleaning apparatus according to the present invention.

FIG. 4 is a schematic plan view showing a third embodiment of the ultrasonic cleaning apparatus according to the present invention.

FIG. 5 is a schematic sectional view of FIG.

FIG. 6 is a schematic sectional view showing a fourth embodiment of the ultrasonic cleaning apparatus according to the present invention.

FIG. 7 is a bottom view of the diaphragm section of FIG. 6;

FIG. 8 is a block diagram illustrating a circuit configuration of a power supply unit according to a fourth embodiment.

FIG. 9 is a graph (a) showing the relationship between the sound pressure and the natural frequency when no frequency modulation is applied to the oscillation source, and graphs (b) to (d) showing the relationship between the sound pressure and the position of each diaphragm. It is.

FIGS. 10A and 10B are specific graphs (a) showing the relationship between sound pressure and position when an oscillation source is frequency-modulated, and graphs (b) showing simplified graphs of (a).

FIG. 11 is a schematic plan view showing an example of a cleaning / drying processing system incorporating the ultrasonic cleaning device according to the present invention.

FIG. 12 is a schematic configuration diagram showing an experimental device for measuring sound pressure of a diaphragm.

FIG. 13 is a schematic plan view (a) showing an arrangement state of a diaphragm to be tested by the above-described experimental apparatus, and graphs (b) to (c) showing a relationship between a sound pressure and a position when the test is performed by appropriately changing a frequency.
It is.

FIGS. 14A and 14B are schematic plan views showing another arrangement state of a diaphragm to be tested by the above-described experimental apparatus. FIG. 14A shows a case where a vibrator is closely attached, and FIG. 14B shows a case where a vibrator is disposed with a gap of 2 mm. Is the case.

15 (a) and (b) when excited at the same frequency in the states of FIGS. 14 (a) and 14 (b) and (c) when excited at different frequencies in the state of FIG. 14 (b). It is a graph which shows the relationship between a sound pressure and a position.

FIG. 16 is a schematic sectional view showing a conventional ultrasonic cleaning device.

FIG. 17 is a graph (a) showing the relationship between the sound pressure and the position of the diaphragm in the conventional ultrasonic cleaning apparatus, and a graph (b) showing the relationship between the particle removal rate and the position.

[Explanation of symbols]

 W Semiconductor wafer (object to be cleaned) 1 Pure water (cleaning liquid) 10 Cleaning tank 40, 40a, 40b, 82 Vibration plates 41a to 41n, 83a to 83c Vibration plate group 50, 50A Oscillation source 51 Frequency modulation (FM modulation) transmission circuit 58 Control circuit 60a-60n Oscillator 81a Main oscillator (power supply unit) 81b, 81c Sub-oscillator (power supply unit) 85 Vibration propagation tank 86 Vibration propagation liquid A power supply PU1-PUn power supply unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-283835 (JP, A) JP-A-8-192123 (JP, A) JP-A-7-171526 (JP, A) 123289 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/304 B08B 3/12

Claims (4)

(57) [Claims] 1. An ultrasonic cleaning apparatus comprising: a cleaning tank containing an object to be cleaned and a cleaning liquid; and a plurality of diaphragms attached to the cleaning tank, wherein an output of a plurality of power supply units for driving the respective diaphragms is provided. An ultrasonic cleaning apparatus characterized in that the same oscillation source controls the same phase to have the same phase. 2. A cleaning tank for storing an object to be cleaned and a cleaning liquid, a vibration transmitting tank for storing a vibration transmitting liquid in contact with a bottom surface of the cleaning tank, and a plurality of diaphragms attached to the vibration transmitting tank. An ultrasonic cleaning apparatus, comprising: controlling the phases of outputs of a plurality of power supply units for driving each of the vibration plates so that the same oscillation source has the same phase. 3. The ultrasonic cleaning apparatus according to claim 1, wherein a gap between adjacent diaphragms is reduced as much as possible. 4. The ultrasonic cleaning apparatus according to claim 1, wherein a variation in the natural frequency of each of said diaphragms is controlled by frequency modulation of an oscillation source. apparatus.